Elle Ashton was pretty sure the "crud" that made her head feel like it was in a crushing vise had morphed into a sinus infection.

But with no health insurance, the 20-year-old college student and part-time restaurant worker said even a trip to MinuteClinic or Target seemed too expensive.

Ashton decided to log on to Virtuwell, an online medical clinic, for a diagnosis instead.

"I was skeptical," said Ashton, of Minnetonka. "But the website was super user-friendly, and took all of 15 minutes to go through the questions."

Web-based medicine is undergoing explosive growth as consumers, health insurers and employers are drawn to the convenience of timely, low-cost care for minor ailments.

Doctors and hospital systems are warming to the notion of round-the-clock e-visits as well, particularly as federal health reform rolls out. With an estimated 30 million Americans expected to gain access to insurance in 2014, finding effective and low-cost ways to divert those with easy-to-diagnose problems such as earaches, pink eye and skin rashes can help alleviate a looming shortage of primary care doctors.

Medicare doesn't cover such visits, but analysts believe it's only a matter of time.

"People have been working on this for three or four years," said Tom Charland, CEO of Merchant Medicine, whose Shoreview company tracks the growth of retail clinics and the changing health care model. "They're starting to figure it out and knock down barriers. When this happens, e-visits and telemedicine are really going to take off."

Ashton said a nurse practitioner called back within a half-hour to follow up, after Ashton noted on the form that she got hives from certain antibiotics. In short order, a prescription for the sinusitis was ready and Ashton was back resting in her "sick bed." Total bill: $44.

"I was worried about giving so much personal information on the computer, but it felt very secure," she said. "I felt like they had my back."

Bloomington-based HealthPartners launched Virtuwell in September 2010 and has relied on a snappy marketing campaign that has included messages on bar coasters, ads about bladder infections on stall doors of women's restrooms and billboards with a giant tissue box.

HealthPartners officials say the number of patients treated through the Virtuwell site tripled in its second year and that more than 40,000 have paid for the service to date.

St. Paul-based Zipnosis launched a similar service after a one-year pilot program with Park Nicollet in 2009. Zipnosis has seen 10,000 patients to date, and expects to double or triple that number in the first six months of 2013. Both Zipnosis and Virtuwell expect to expand into new states and develop mobile applications in the next quarter.

"It was sort of a controlled release," said Zipnosis CEO Jon Pearce, one of the founders. "Now there's less concern with regulatory pressure. Employers are signing up for the service and we're partnering with health systems. There's more reliable volume and a high repeat rate."

Both Virtuwell and Zipnosis rely on licensed nurse practitioners and physician assistants to treat a limited set of common ailments. People with urgent issues or who need to be seen in person are given referrals.

Virtuwell handles insurance claims with more than a dozen major insurers, in addition to its own HealthPartners' plan. Zipnosis provides a claim for patients to file on their own.

The sites charge a fraction of the cost of other doctors' visits and services. Virtuwell costs $40, while Zipnosis is $25. Compare that to an average emergency room visit of $250 to $300 in the Twin Cities or a trip to a doctor's office of $120 to $200. MinuteClinic or TargetClinic typically cost around $75.

Zipnosis, which also has a partnership with Fairview Clinics, estimates its online clinics have saved $1.5 million in costs for people who would have gone to the emergency room or urgent care.

"As more people go into high-deductible and health savings account plans, our service offering starts looking pretty good compared to other choices," said Kevin Palattao, a HealthPartners vice president who oversees Virtuwell. "More and more, consumers are responsible for that first dollar of care. They're going to seek out those experiences that bring high quality of care and offer more convenience in their lives."

Low-cost option

Hom Furniture began offering Virtuwell to its 970 employees last year. They get access to Virtuwell for free or for a $10 co-pay, depending on which benefit plan they choose.

The company, which also operates Gabberts and Dock 86, is self-insured and keen on keeping costs down and employees healthy and working.

"Employees are loving the fact that they don't have to go into clinics where they'll catch other illnesses," said Wendy Rolfer, Hom's human resource benefit administrator. "For Hom, that would be a $200 visit for us."

The global market for telemedicine, which also includes phone calls, video chats and other online visits with doctors, is expected to more than double over the next five years to $27.3 billion, according to a recent report from the market research firm BCC Research.

Eden Prairie-based Optum, part of UnitedHealth Group Inc., launched NowClinic in 2010, and it now operates in 21 states, including Minnesota, Wisconsin and the Dakotas. It typically costs $45 for a 10-minute online consultation, but doesn't handle insurance.

The Cleveland Clinic's MyConsult markets itself as an online second opinion for complex illnesses, including cancer and heart illness. The service doesn't handle insurance and costs $565 to $745, which can include a review of pathology reports.

Zipnosis' Pearce described Minnesota as the "epicenter" of e-visit innovation. One of Zipnosis' founders also launched the precursor to today's MinuteClinic in the Twin Cities in 2000.

"To see two commercial products generating this much volume is unique in the country," he said. "It's a receptive market in general from the health care perspective."

The concept still faces skeptics, particularly as retail clinics move into prevention efforts for people with chronic diseases such as diabetes, asthma and heart failure. A "virtual" consultation can't replace face-to-face care, opponents say.

Gwen Verchota, a nurse practitioner for Virtuwell, doesn't disagree. There are times, she said, when she'll pick up the phone and call a patient so she can hear the baby's cough or listen to someone's hoarse voice. And she's not shy about sending people to a bricks-and-mortar clinic or to deny someone an antibiotic prescription when it's not necessary.

"We're going to follow the evidence and practice using current science," she said. "The cases that stand out are people who don't have insurance and are so appreciative of getting some good, common-sense guidelines."